RESUMEN
Optical vortices are currently one of the most intensively studied topics in optics. These light beams, which carry orbital angular momentum (OAM), have been successfully utilized in the visible and infrared in a wide variety of applications. Moving to shorter wavelengths may open up completely new research directions in the areas of optical physics and material characterization. Here, we report on the generation of extreme-ultraviolet optical vortices with femtosecond duration carrying a controllable amount of OAM. From a basic physics viewpoint, our results help to resolve key questions such as the conservation of angular momentum in highly nonlinear light-matter interactions, and the disentanglement and independent control of the intrinsic and extrinsic components of the photon's angular momentum at short-wavelengths. The methods developed here will allow testing some of the recently proposed concepts such as OAM-induced dichroism, magnetic switching in organic molecules and violation of dipolar selection rules in atoms.
RESUMEN
We conducted a systematic review of guidelines on the management of low back pain (LBP) to assess their methodological quality and guide care. We synthesized guidelines on the management of LBP published from 2005 to 2014 following best evidence synthesis principles. We searched MEDLINE, EMBASE, CINAHL, PsycINFO, Cochrane, DARE, National Health Services Economic Evaluation Database, Health Technology Assessment Database, Index to Chiropractic Literature and grey literature. Independent reviewers critically appraised eligible guidelines using AGREE II criteria. We screened 2504 citations; 13 guidelines were eligible for critical appraisal, and 10 had a low risk of bias. According to high-quality guidelines: (1) all patients with acute or chronic LBP should receive education, reassurance and instruction on self-management options; (2) patients with acute LBP should be encouraged to return to activity and may benefit from paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs), or spinal manipulation; (3) the management of chronic LBP may include exercise, paracetamol or NSAIDs, manual therapy, acupuncture, and multimodal rehabilitation (combined physical and psychological treatment); and (4) patients with lumbar disc herniation with radiculopathy may benefit from spinal manipulation. Ten guidelines were of high methodological quality, but updating and some methodological improvements are needed. Overall, most guidelines target nonspecific LBP and recommend education, staying active/exercise, manual therapy, and paracetamol or NSAIDs as first-line treatments. The recommendation to use paracetamol for acute LBP is challenged by recent evidence and needs to be revisited. SIGNIFICANCE: Most high-quality guidelines recommend education, staying active/exercise, manual therapy and paracetamol/NSAIDs as first-line treatments for LBP. Recommendation of paracetamol for acute LBP is challenged by recent evidence and needs updating.
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Terapia por Acupuntura , Antiinflamatorios no Esteroideos/uso terapéutico , Terapia por Ejercicio/métodos , Dolor de la Región Lumbar/terapia , Manipulaciones Musculoesqueléticas/métodos , Humanos , Dolor de la Región Lumbar/tratamiento farmacológico , Ontario , Revisiones Sistemáticas como AsuntoRESUMEN
OBJECTIVE: The objective was to develop a clinical practice guideline on the management of neck pain-associated disorders (NADs) and whiplash-associated disorders (WADs). This guideline replaces 2 prior chiropractic guidelines on NADs and WADs. METHODS: Pertinent systematic reviews on 6 topic areas (education, multimodal care, exercise, work disability, manual therapy, passive modalities) were assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR) and data extracted from admissible randomized controlled trials. We incorporated risk of bias scores in the Grading of Recommendations Assessment, Development, and Evaluation. Evidence profiles were used to summarize judgments of the evidence quality, detail relative and absolute effects, and link recommendations to the supporting evidence. The guideline panel considered the balance of desirable and undesirable consequences. Consensus was achieved using a modified Delphi. The guideline was peer reviewed by a 10-member multidisciplinary (medical and chiropractic) external committee. RESULTS: For recent-onset (0-3 months) neck pain, we suggest offering multimodal care; manipulation or mobilization; range-of-motion home exercise, or multimodal manual therapy (for grades I-II NAD); supervised graded strengthening exercise (grade III NAD); and multimodal care (grade III WAD). For persistent (>3 months) neck pain, we suggest offering multimodal care or stress self-management; manipulation with soft tissue therapy; high-dose massage; supervised group exercise; supervised yoga; supervised strengthening exercises or home exercises (grades I-II NAD); multimodal care or practitioner's advice (grades I-III NAD); and supervised exercise with advice or advice alone (grades I-II WAD). For workers with persistent neck and shoulder pain, evidence supports mixed supervised and unsupervised high-intensity strength training or advice alone (grades I-III NAD). CONCLUSIONS: A multimodal approach including manual therapy, self-management advice, and exercise is an effective treatment strategy for both recent-onset and persistent neck pain
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Humanos , Lesiones por Latigazo Cervical/terapia , Dolor de Cuello/terapia , Manipulación Quiropráctica , Lesiones por Latigazo Cervical/diagnóstico , Modalidades de Fisioterapia , Enfoque GRADERESUMEN
The aim of this study was to develop and characterize hydrophilic gels containing chlorophyllin(CHL)-loaded liposomes as well as to evaluate their stability. Two different CHL-loaded liposome dispersions using non-hydrogenated and hydrogenated soybean lecithin were prepared, characterized for their particle size, polydispersity index and trapping efficiency and incorporated in Carbopol 940 NF hydrogel. The gels obtained were analyzed for flow properties, pH values and CHL content. The control liposome-free gel was obtained by incorporating the CHL solution in the hydrogel. The stability of the gels was evaluated in terms of rheological properties, pH values and CHL content during 6 months' storage at 20 +/- 2 degrees C. Suitable gel formulations for topical use were obtained revealing shear-thinning plastic flow behaviour without significant thixotropy during the whole period of examination. High yield values of the samples during the whole period indicated a long-term stability of the gel formulations. The gel formulations expressed a mild acid value acceptable for topical preparations. After 6 months' storage the CHL content was highest in the gel containing non-hydrogenated lecithin liposomes, followed by the gel containing hydrogenated lecithin liposomes and liposome-free gel, indicating that the encapsulation of CHL in liposomes led to a greater stability of CHL.
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Antimutagênicos/administración & dosificación , Clorofilidas/administración & dosificación , Resinas Acrílicas , Antimutagênicos/química , Clorofilidas/química , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Geles , Concentración de Iones de Hidrógeno , Liposomas , Tamaño de la Partícula , Reología , ViscosidadRESUMEN
Pemulens(R) (BF Goodrich) are hydrophobically-modified copolymers of acrylic acid (Acrylates/C10-C30 alkyl acrylates) that could act both as primary emulsifiers for o/w emulsions and viscosity enhancing agents. The aim of this study was to assess the influence of different processing conditions (mixing equipment, speed and time of agitation) on the aesthetic characteristics, viscosity and physical stability of o/w emulsion gels based on the polymeric emulsifier (Pemulen TR-2 NF). This objective was achieved by applying a two-factor three-level experimental design at two sets: using a laboratory mixer and a disperser. Independent variables were mixing speed and time and dependant variables i.e. responses, were millimetres of oil phase separated after centrifugation at 3500 rpm in a laboratory centrifuge, and viscosity at shear rate 180 l/s. The responses were fitted into a second order model by means of a multiple regression analysis. For the samples prepared on the laboratory mixer it was shown that mixing time and speed produce a statistically important influence on viscosity, but not on physical stability: with increasing mixing speed and time the viscosity linearly increases. If we assume that greater energy input obtained by increasing the mixing speed and time produces a decrease in drop size and polydispersity and better developed gel network, then the optimal processing conditions will be at the point where maximal viscosity is attained. This result was in accordance with the centrifugation test - the best stability appeared when maximal mixing speed and time were applied, although this effect appeared not to be statistically significant. For samples prepared using dispersers no statistically important influence of processing variables on viscosity and physical stability was found. Additionally, emulsion samples prepared using the laboratory mixer appeared homogenous, while in samples prepared using the disperser, undispersed polymer lumps appeared. Based on physical characteristics of the emulsions, it could be concluded that the disperser is an inappropriate tool for processing the emulsions based on Pemulen polymers.
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A gene coding for a protein that shows homologies to prokaryotic ribosomal protein S2 is present in the mitochondrial (mt) genome of wheat (Triticum aestivum). The wheat gene is transcribed as a single mRNA which is edited by C-to-U conversions at seven positions, all resulting in alteration of the encoded amino acid. Homologous gene sequences are also present in the mt genomes of rice and maize, but we failed to identify the corresponding sequences in the mtDNA of all dicotyledonous species tested; in these species the mitochondrial RPS2 is probably encoded in the nucleus. The protein sequence deduced from the wheat rps2 gene sequence has a long C-terminal extension when compared to other prokaryotic RPS2 sequences. This extension presents no similarity with any known sequence and is not conserved in the maize or rice mitochondrial rps2 gene. Most probably, after translation, this peptide extension is processed by a specific peptidase to give rise to the mature wheat mitochondrial RPS2.
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ADN Mitocondrial/genética , Grano Comestible/genética , Genes de Plantas/genética , Proteínas Ribosómicas/genética , Triticum/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN de Plantas/genética , Datos de Secuencia Molecular , Plantas/genética , Edición de ARN , ARN Mensajero/análisis , ARN de Planta/análisis , Mapeo Restrictivo , Análisis de Secuencia de ADN , Homología de Secuencia de AminoácidoRESUMEN
We investigated common length polymorphism caused by a variable number of tandem repeats in the hypervariable region located at the 3' end of the human apolipoprotein B gene in 696 Serbian (Belgrade area) unrelated individuals of both genders. After using the polymerase chain reaction to amplify this polymorphic region, 17 different alleles, containing 22-54 repeats, were distinguished. The bimodal distribution and the heterozygosity index (average 0.71) obtained in both genders are similar to those reported for other Caucasian populations. However, the HVE34 allele was found to be the commonest in both female and male samples. There was also a lower frequency of the HVE > 36 alleles than in other Caucasian populations studied.
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Apolipoproteínas B/genética , Variación Genética/genética , Repeticiones de Minisatélite/genética , Femenino , Frecuencia de los Genes , Genes/genética , Humanos , Masculino , YugoslaviaRESUMEN
1. The endogenous, NADPH-supported production of H2O2 and of O2-.-radicals in liver microsomes, was very strongly enhanced in the presence of 1-nitroso-2-naphthol. 2. A 30-fold induction by NON was the consequence of its direct reduction to NON-radicals, catalyzed by microsomal NADPH:cytochrome P450 reductase. 3. Nitroso radicals reduce molecular oxygen to superoxide anion radicals, which were readily dismutated by superoxide dismutase to hydrogen peroxide. 4. O2-.-radicals were the sole precursors of all NON-induced production of H2O2 in liver microsomes.
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Microsomas Hepáticos/enzimología , NADP/metabolismo , Compuestos Nitrosos/metabolismo , Animales , Radicales Libres , Peróxido de Hidrógeno/metabolismo , Masculino , NAD/metabolismo , NADPH-Ferrihemoproteína Reductasa/metabolismo , Oxidación-Reducción , Ratas , Ratas Sprague-Dawley , Superóxido Dismutasa/metabolismo , Superóxidos/metabolismoRESUMEN
Suspensions of indometacin (1% w/v), buffered to pH 5.6, may be satisfactorily preserved by 0.002% w/v phenylmercuric nitrate in the presence of hydroxypropylmethylcellulose (0.5% w/v), despite 90% of the preservative being adsorbed to the indometacin powder. Polyvinyl alcohol (1.4%) could be used as an alternative suspending agent.
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Indometacina/análisis , Adsorción , Compuestos de Benzalconio/análisis , Incompatibilidad de Medicamentos , Almacenaje de Medicamentos , Escherichia coli/análisis , Derivados de la Hipromelosa , Metilcelulosa/análogos & derivados , Soluciones Oftálmicas , Compuestos de Fenilmercurio , Alcohol Polivinílico , Espectrofotometría Ultravioleta , SuspensionesRESUMEN
Pigeon erythrocytes were carefully washed in an isotonic neutral buffer, devoid of potassium, and the rate of passive unidirectional efflux of potassium from the cells into a K+-free medium was measured after 20 min, at 40 degrees C. Isoproterenol inhibits K+-efflux by 35-45%, at a cell concentration of 1%; the isoproterenol effect is mediated by beta-adrenergic receptors. Cyclic AMP mimics the effect of isoproterenol, but at 4-5 orders of magnitude higher concentrations. Cyclic AMP increases 20-fold the phosphorylation of purified cell membranes by [gamma 32P]ATP.